Preparation of a nano-clay-based super absorbent polymer composite for water absorption applications

Incorporation of naturally occurring fillers like clay and other mineral improves mechanical, chemical, and physical properties. Herein, we report for synthesized nano-clay based superabsorbent polymer by graft copolymerization of acrylic acid and acrylamide This study focusses the effects of filler (nano-clay), crosslinking agent and initiator concentration on the absorption of the copolymer. Six specimens with varying percentages i.e., 30, 32, 34, 36, 38 and 40 wt. % were supplemented with nano-clay in the matrix of the polymer. Time based immersion was carried out in tap, de-ionized and brine for 2 to 24 h the superabsorbent polymer with 36 wt.% of nano-clay absorbed highest percentage i.e., up to 18 folds after submerging in tap water for 2 hours. Detrimental trend of absorption was observed in specimens with 38 and 40 wt. % that could be due to surge in formation of physical and chemical cross-linking networks in the polymer matrix. However, suspension of superabsorbent polymer composite in brine resulted in decreased absorbency. Such course was also observed for specimens containing 36 wt. % of nano-clay after submerging for 4, 6 and 24 hours. Thermal stability analysis also revealed that the polymer composite supplemented with 38 wt. % of nano-clay exhibited ameliorated stability to 350 degrees C.